See the next paragraph in the FAQ you posted:
The difference between this and “incorporating” the GPL-covered software is partly a matter of substance and partly form. The substantive part is this: if the two programs are combined so that they become effectively two parts of one program, then you can't treat them as two separate programs. So the GPL has to cover the whole thing.
It does not matter if you interface with a GPLv3 program by calling a binary or by loading a dll, as long as you present the resulting program as one program the GPL applies.